Lesson 2: Protein power: protecting health, strength & satiety
This lesson will help you understand how much protein you actually need and how to meet that goal consistently with a smaller appetite.
Lesson 2 of 12 · Nutrition with Megan, RDN · Megan Ostler, MS, RDN
What is protein?
Protein is made of long chains of amino acids, the building blocks your body uses for repair and renewal. There are 20 amino acids total, and 9 are essential (meaning they must come from food).
Think of it like this:
- Amino acids are like letters in the alphabet
- Those letters form words: proteins
- Proteins come together into sentences: tissues, enzymes, and hormones that tell your body's story
- Together, they create the novel: you
During digestion, protein is broken back down into amino acids and used to create new proteins your body needs.
Protein: The building blocks of the body
Protein is the raw material that builds your skin, hair, organs, and bones. Inside your cells, protein becomes enzymes that spark the reactions keeping you alive, from digesting food to signaling cell formation.
How it works:
- Builds and repairs every tissue in the body
- Forms enzymes and hormones that regulate body functions
- Supports immune function and recovery from illness and stress
Protein also influences how you feel: it slows digestion and triggers fullness hormones like GLP-1 and PYY.
Why protein matters now (on GLP-1s)
Muscle is metabolically active: it burns calories even at rest, stabilizes blood sugar, and gives you strength and stamina.
The challenge:
- Risk of inadequate intake due to overall reduction in calories
- Inadequate protein increases muscle loss while in a calorie deficit
The opportunity: With proper nutrition and activity, muscle mass can be spared during weight loss.
The science of muscle maintenance
Your body is always building and breaking down muscle. Protein keeps the balance.
Muscle protein synthesis (building)
- Eating protein provides amino acids, your body's building blocks
- These amino acids rebuild and repair muscle
- A steady supply keeps your amino acid pool stocked for building
Muscle protein breakdown
- When amino acid levels drop, the body breaks down muscle for fuel
- Illness, stress, and under-eating accelerate this breakdown
- Without enough dietary protein, you "borrow bricks" from your own wall
Bottom line: Regular protein intake keeps your body building instead of breaking down.
Protein and satiety
Protein is one of the most satisfying macronutrients. Here's why:
- Boosts GLP-1 and PYY (fullness signals)
- Stabilizes blood sugar and energy
- Reduces late-day cravings
Science highlight: Protein has a high thermic effect of food (TEF): about 20-30% of its calories are used just to digest and absorb it. This means your body works harder to process protein, which can support metabolism.
Protein and metabolism
Why this matters:
- Muscle burns calories, even at rest
- More muscle = easier weight maintenance
- Protein intake protects your metabolism
Target protein intake: 1.2 to 2.0 g/kg body weight per day
The formula:
- Strength training + quality protein = better muscle preservation
- This is why nutrition isn't optional, it's protective
How much protein do you need?
Your protein needs depend on your activity level and goals. Here's a quick reference:
Goal | Protein Target
Prevent deficiencies | 0.8 g/kg/day
General population | 1.0-1.2 g/kg/day
GLP-1 medication | 1.2-2.0 g/kg/day
Athletes | 1.5-2.0 g/kg/day
Build muscle | 1.75-2.0 g/kg/day
Note: This may need to be adjusted based on overall calories. I don't recommend exceeding 40% of your calories from protein.
Calculate your protein goal
Step 1: Convert your weight to kilograms
- My weight (lbs) ÷ 2.2 = my weight (kg)
Step 2: Multiply by your target range
- For most people on GLP-1s: multiply by 1.2 to 1.6
- For those over 50, exercising frequently, or trying to build muscle: multiply by 1.5 to 2.0
Example: 185 lb woman, age 35, lightly active
- 185 ÷ 2.2 = 84 kg
- 84 × 1.2 = 101 g protein (low end)
- 84 × 1.6 = 134 g protein (high end)
- Target range: 101-134 g/day
How protein works throughout the day
It's not just about eating enough protein. It's about using it consistently to help your body feel balanced and capable from morning to night.
Benefits of spreading protein throughout the day:
- Replenishes amino acid pool for building and repair
- Stabilizes blood sugar and hunger, which reduces cravings
- Supports mood, focus, energy and keeps metabolism active
Aim for at least 25 g of protein at meals to stimulate muscle protein synthesis (MPS) and support ongoing repair.
Practical ways to meet your target
Quick reference: Protein at each meal
Meal | Protein Goal | Example Foods
Breakfast | 25-30 g | Greek yogurt, eggs, protein oats, cottage cheese
Lunch | 25-30 g | Chicken, tofu, cottage cheese, tuna
Dinner | 25-30 g | Fish, lentils, edamame, lean beef
Snack(s) | 10-20 g | Nuts, protein shake, cheese stick, kefir
Easy protein portions
- 3 oz chicken or fish ≈ 25 g protein (about the size of a deck of cards)
- 1 cup Greek yogurt or cottage cheese ≈ 20-25 g protein
- 1 cup lentils or edamame ≈ 15-18 g protein
For low-appetite days
Choose liquid protein options like:
- Smoothies with protein powder
- Greek yogurt drinks
- Ready-to-drink protein shakes
- Kefir
These are easier to sip and digest when solid foods feel heavy.
Tips for meeting your protein goal
Get protein from a variety of sources:
- Include both animal and plant proteins throughout the week
- Plant proteins (beans, lentils, tofu, tempeh) come with added fiber
On lower-appetite days:
- Prioritize protein first at meals
- Use softer textures that are easier to eat (scrambled eggs, cottage cheese, smoothies)
- Sip protein shakes between meals
Track for 3 days:
- Write down what you eat and estimate protein grams
- Notice patterns: Are you getting protein at every meal? Which meals are lowest?
- Adjust based on what you learn
Your action steps this week
Step 1: Calculate your protein target (1.2 to 2.0 g/kg body weight)
Step 2: Break it down by meal
- Aim for at least 25 g protein at breakfast, lunch, and dinner
- Add 10-20 g through snacks
Step 3: Track for 3 days
- Note your protein intake at each meal
- How did you feel? More energy? Less hungry between meals?
Weekly goal = skill you practice this week:
- Add a protein-rich food to each meal
- Include a protein snack between meals
- Try one new protein source this week
Minimum habit = simpler version for busy days:
- Add protein at one meal
- Have a protein-based snack
- Prioritize protein at breakfast
Reflection prompts
At the end of the week, reflect on:
- What helped me meet my protein goal?
- How did I feel on days I hit vs. missed my target?
- Was my energy steadier? Did I have fewer cravings?
Key takeaway
Fueling your body well today protects the strength you'll rely on tomorrow.
Next lesson
Lesson 3: Fiber, fluids & fullness
Learn how to support digestion, reduce bloating, and stay hydrated when appetite is low.
Download resources
Lesson 2 Worksheet (PDF): Calculate your protein target, plan protein at each meal, and track your intake for 3 days
50 Easy Ways to Add Protein Guide (PDF): Quick reference for protein-rich foods and simple meal ideas
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This information is for educational purposes and does not replace medical advice.
Education only, not medical advice.
